Had an echo and stress test 2 yrs ago with normal results but am now exp hard pvc's stopping me dead in my tracks. Dangerous if my tests were normal?

2 years ago. Your normal tests were 2 years ago, things change. If your symptoms are troubling seek medical advice.
See a doctor! If you chest palpitations or pain stop you from exerting yourself , i would not feel comfortable of you did not have them evaluated by a doctor. 2 years ago does not necessarily reflect what is happening today.
Not usually. Pvcs, especially with a recent normal stress test, are typically benign. However, they can be harmful to your heart if they are very frequent (>20% of all beats). You should have a 24 hr holter to get an idea of how frequent your pvcs are, and to see if you have any other rhythm issues.